"Watching you suffer in pain is much more entertaining than watching television."

This is one example of the witty comments Chiaki says to her older sister Kana. She is the youngest of the three Minami sisters, yet also the most cynical. She looks down upon those below her in intelligence (with various insults frequently heard from her lips). It doesn't mean that she's infallible, though. Sometimes, she gets swept by her moronic sister's ill logic and, on very rare occasions, she intellectually fumbles (with burning embarrassment afterward). Her pretentious know-how can often backfire, making her overanalyze simple things, sometimes leading to humility on her part.

When "Princess" Chiaki commands, others obey; yet she herself obeys her eldest sister with loyalty befitting a sister complex. She views Haruka as a role model and gives her much respect. In class, she is often in charge while other classmates are either afraid or in awe. She thinks of herself as superior to most, and often enjoys teasing Kana, such as misleading her to believe her acquaintances are secretly plotting against her. While capable of stringing together eloquent insults, Chiaki can have fun as a girl (with a semi-deadpan demeanour): teddy bears, eating cake, and ordinary light talk.